Jun, Jul, Aug, Sep, Oct
At its best:
Choose potted irises carrying several clusters of healthy leaves. Lift out of their pots and look for healthy roots.
Dig a planting hole that is just deep enough to take the rootball. Choose a sunny site with a well-drained soil. You can improve drainage in your soil by digging in plenty of grit before planting.
Settle the rootball into the hole so it's level with the surrounding soil. Backfill with soil, then firm around the plant. Achieve the best effect by positioning plants in bold groups, with multiples of the same variety growing together.
Ensure the rhizome is on the surface of the soil and not covered with soil, so it's exposed to the sun. Trim neighbouring plants, if necessary, so they don't cast shade over your irises.
Water the whole area thoroughly, to settle the soil and remove air pockets. Only water again if the soil is very dry. Feed early in the season with a low-nitrogen fertiliser such as bone meal.
Mulch the soil with gravel, to retain moisture, but don't cover the rhizomes. Deadhead irises after flowering by cutting stems back to the fan of leaves. Plants will bloom again next spring.